Gonna check diff & Trans today....

[CGauthier]

I wanna check my driveline over today-change&overfill my trans and change the diff oil and inspect... . I've never inspected a diff before, in fact I've never even taken a cover off From what i gather when i put the cover back on I have to make my own seal? With what permatex? Sorry for being so elementary guys... but i am taking an agressive approach to learning my truck inside out, and i need your help The transmission I THINK i can handle any tips welcome thou. 1st Gen day if i can make it i'll try and repay you all



Tia



Carl G

 

[tugboatphil]

Carl,



I've looked inside several, and can honestly say I don't know much more than if I never had. There's lots of little stuff that needs attention that I don't have. I can say that when you refill, there is a special oil additive that is required for a LSD. It has to do with making the slip clutches work properly.



There have been several recent posts concerning this, and I believe that Pastor Bob addressed the additive issue in it. Do a search on that and see what comes up.



Good Luck!

 

[MrWinkey]

I wouldnt recomend permatex.



They make a gasket. I would use that instead. Works much better. As in the other thread DONT OVERFILL!

 

[CGauthier]

Oh, sorry i do know about the friction modifier... . I guess what i'm gona be lookin for is metal shavings or anything like that in the pan. I thought i read one of your posts tugboat Phil sayin that they didnt make that gasket anymore. Actually I'm wondering if i even have to (or should) take the cover off... . I guess you could tell enough by the oil couldn't ya. It's gona take alot to get my wifes car outa tha garage tho... lol the weather is ridiculous out here, I'm gona take a pic and show you guys why i'm having such a hard time making $$$.



P. s. And I'll make sure i dont overfill How much oil does that sucka take? One more thing... . I've heard about heavy and hot (heavier oils) what about heavy and cold? I dont no if I'll change the oil again b4 winter or not but I wonder how the heavier oil would effect the diff in sub zero temps? Another debate im having is whether or not to put lucas oil stabilizer in the trans or not. I dont think im gona bother putting that in the diff. Sorry if these questions are annoying you guys; I'm not the smartest guy here thats for sure-dont be afraid to tell me to stfu lol

 

[paccool]

Manual says to use RTV gasket maker. I never had a problem with leaks using it, never used a manufactured gasket.



I just put on a Mag-Hitec cover so hopefully it will never have to come back off.

 

[CGauthier]

Originally posted by paccool

Manual says to use RTV gasket maker. I never had a problem with leaks using it, never used a manufactured gasket.



I just put on a Mag-Hitec cover so hopefully it will never have to come back off.

Dammit yer getting all the goodies! If we could ever get some decent working weather i can make alot of $$ pretty fast... and be assured when i do the ppl here will be the first to know even before my wife lol.

 

[dan brooks]

Look at the fluid that comes out for any metal shavings, large chunks, etc. Feel around in the bottom of the housing - there is a little "pool" under the ring gear where any larger bits and pieces might get trapped. The problem with mine was obvious - I had several damaged shims stuck to the magnet (looked like crumpled strips of aluminum foil). Hopefully you won't find anything unusual and this will just be a routine fluid change.



Before scraping or cleaning the old gasket off, stuff paper towels or a rag around the opening to keep the debris from getting inside. Make sure the sealing surfaces are clean and smooth before replacing the cover - I use a ScotchBrite "cookie" on my die grinder, which takes all of two minutes to clean both sides.



For several years, most vehicles have come from the factory with silicone instead of a gasket. I've always used the red hi-temp silicone and have never had one leak... but have had one with a gasket drip. Run about a 1/8" bead all the way around - it doesn't take much - and bolt the cover back on. Don't forget to refill... .

 

[CGauthier]

You didnt tell me to stfu Dan, I'm happy about that So if the oil seems clean dont bother taking the cover off? Or i should regardless?



OK... you guys wanna know why i dont even have guages? Here's my excuse.....



#ad




and another



#ad




Unbelievable, that's all i can say. It's May for cryin out LOUD



P. S. Do you have to let that Silicone/rtv gasket maker dry awhile before you refill? I guess I'm gona go with 85-140 syn like bgilbert suggested... . well I'm gonna go out oil shopping now... . wish me luck

 

[dan brooks]

There is no harm in asking questions - that's how you learn. Besides, I'd never tell anyone on here to stfu - if I didn't want to hear from them I'd just ignore 'em. Never have understood people getting worked up because of the internet.



I'd still change the fluid, even if it looks clean. I do mine once a year, just before I leave for vacation. Probably overkill, but I feel more comfortable having a chance to look things over before taking a 3500-mile trip.



I don't wait for the RTV to dry before filling up and haven't had a problem.

 

[bgilbert]

CG, yes you pretty much have to take the cover off to drain the diff fluid. You could loosen all of the top bolts and remove the bottom and let the fluid drain, but why not remove the top bolts since you're already there, so you can inspect the inside, plus once you break the gasket seal, the cover has to come off, for a new seal be it a gasket or silicone. If you have an air compressor, use brake cleaner to spray the inside of the diff, to get out all the old oil and clean things. Then use the compressed air to blow it all dry, plus helps get the oil from the 'pool' in the back. Scrape all old gasket or silicone from the diff housing and diff cover.

P. S. Do you have to let that Silicone/rtv gasket maker dry awhile before you refill?

No, but I do. I give a few hours, if you don't need the truck right away, give it til the next morning. If 4x4 do both front and rear diffs at this time, LSD in front as well. T-case fluid change 80-90wt gear oil , getrag fluid. If you buy Mobil1 synthetic 5w30 for the getrag, you can reuse an empty gear oil bottle, since the mobil1 qts have the big mouth and a pump wont screw down onto the bottle. Squirt the 5w30 thru the fill hole, til it runs out, put plug back in. Then remove the top PTO cover bolt and fill the last 1-1. 5 qts thru it.

Oh yeah and once the diff cover is back on, put in your friction modifyer in first, then gear oil. Winter time take it easy for a few miles so that the 85-140 can get moving, same if you had 80-90 though, but I wouldnt worry bout it.

I'm not a fan of synthetic in t-case of diffs. Synthetic just loves those old seals and small holes/leaks. Yeah its a old myth but it happens... Stick with conventional gear oil and simply change it at the recommened interval. Say no to Lucas, unless were talking injectors. I could go on and on, but once you do this once, you'll be a pro and will tell another first timer the ropes. Just get under there and take it apart and put it back together. Bill

 

[RobbieH]

You don't have to worry so much about the gasket material or silicone material getting into the works when you are scraping it all off. I've worked on a rear end recently where 4 of the ring gear bolts came off and the diff simply chewed them up like candy, there were no marks on the ring gear or pinion gear at all.



Besides, once I get all my gasket stuff off, I always spray everything down with brake cleaner or carb cleaner to get all the old junk out. Mainly I do this because it makes it easier to inspect everything.



And Permatex is fine for putting your diff cover back on. Make sure the surface has a decent thin coat, then bolt the cover back on. Typically at this point I stop and have a beer or two, then fill it on up. I've never had one leak on me yet.

 

[CGauthier]

Well, I wasted my afternoon running all over town (very slowly because of the road conditions )looking for oil and friction modifier. I wanted 85-140 synthetic which I could not find it except for a 5 gal pail for $150. I wanted to maybe put something just a little heavier in the trans than 5w30 just because of the heavy load-and i found 5-40 and 5-50 synthetic only in the Castrol brand, but wanted to check with you guys first And, friction modifier made me very uneasy to buy any of the two options i found. At Oil Mart they had one, but the guy said it made the LSD grab more, so a positive effect... . whereas from what i gathered here friction modifier was supposed to make it slip a little easier (negative effect) The other i just had no idea what it was about so i said to myself i'm just gonna order from the net (I was getting irritated). O another finding i found was a 5-40 synth made by Texaco for diesel engines(Canadian, i dunno if you know what that is) they say everybody seems to love. Anyways I'd like to gather a few opinions on what weight of oil I probably SHOULD use for the trans and I'd like a little more info on the friction modifier... . I'd like to just order it online then i no i got the right stuff.



BGilbert(Mind if i call ya Bill?) You figgure maybe having a little heavier synth like 85-140 would help the leak faktor? Just wondering... I thought synth might keep things a little cooler but if its gona leak thats no good.



Not much fun today lol

Carl G

 

[bgilbert]

Well the old myth is: a synthetic will make a small leak a big leak and a big leak a bigger leak or something like that. I think the synthetic molecules are smaller than dino molecules, there is good reading on this via the search. I know I've run synthetic in t-cases and soon after front and or rear output seals start leaking badly. Plus have read that some have had to do rear wheel seal jobs after a diff change to synthetic... . I could be wrong. But I believe it.

Anything sythetic is gonna co$t more. Yes syn will keep things cooler. But could cause leaks. The leak factor has nothing to do with the weight of oil IMO.

Don't buy into much of what the parts guy tells ya. Just buy a 7oz tube of LSD and install.

Trans oil: I think most are using 5w30. Some 5w40,50 0w-whatever ATF, gear oil, so on and so forth. If finding all this great stuff is difficult, I imagine that Texaco 5-40 syn would do fine.

Yes my name is Bill. If it were me, I'd try to find Mobil one syn 5w30 engine oil for the trans. Any quality coventional (dino) 85-140 gear oil for rear diff + 7oz tube of friction modifyer.



Don't know any places online to buy. I'm sure there's many vendors out there. BILL

 

[TMWeber]

I just changed my front and rear recently. I used redline 75-90 (synthetic), no friction modifier, and I have no chatter or noise at all. I used black silicone. I let it sit for about 10 minutes after making the bead-just until it got a bit tacky- then bolted it up! Filled it right away and test drove it (DON'T OVER FILL) Was a simple job. Thanks to everyone in TDR land for the info on 'how to'. Also Bill (may I too call you Bill?) your info on spraying with brake cleaner and drying with air worked nice! but I was wondering, are there any parts or seals that could be damaged by the brake cleaner?

 

[paccool]

Carl,



When all else fails, go to your Dodge dealer for the limited slip additive. The stuff they have works well. Of course it is a little more expensive!



Stan

 

[bgilbert]

but I was wondering, are there any parts or seals that could be damaged by the brake cleaner?

I don't know. I guess if some was left in there and didn't dry then after filling with gear oil it might eat away at the wheel seals?? I have no idea... I've done a few diff's and haven't had any leaks or seals go bad, knock on wood. I've even done a couple diff services when I didnt have compressed air, just had to use a shop rag to help get the 'pool' of brake cleaner and gear oil out the back, then let it air dry til the next day, didn't run into any problems afterwords.

You all can call me Bill.

Bill<-- by no means a ASE certified mechanic. Just read the books a few times and got my hands dirty a few more times.

 

[CGauthier]

I'm glad that we got that out of the way that we can call you Bill Hmmm I didnt think i had to put friction modifier in the front diff, the guy at Dodge said it was obvious you didn't have to, but then what the hell do they know?Well, I guess I'm gonna have to make another trip O well--thanks for all your help Bill And thanks to everyone else in this thread too Well, time to get dirty



Thanks all,

Carl G

 

[CGauthier]

Well, i did both diffs, all went good The only funny thing i noticed was on the magnet in the rear diff there was a silverish paste, kinda looks like that rad stop leak or something like that. I changed the oil in the engine(to get that Lucas stuff out) and i did the transmission too... except I'm not able to get the stick shift back in Other than that I think my truck loves me today that brake cleaner and air compressor worked great Bill, thanks



Carl G

 

[dan brooks]

The silver paste is typical and nothing to worry about. Unless you found any slivers, chunks, etc. , it sounds like it's all good.



Can't help on the shifter - if it's anything like the transmission in my '78 Dodge P/U it's a real pain to push in and turn.

 

[CGauthier]

Those are great words to hear Dan, thanks! Ever done a KDP? Just kidding lol... I'm not ready to do that little sucker yet.



L8rz... .

Carl G